couple of questions for someone familiar with torrents

[d3adf1sh 1]

1) so i don't do a lot of torrenting but sometimes i'll download music torrents which not many people do these days so i'll seed for a bit longer than usual.  but sometimes i'll notice after it's been up for a while i'll see a peer trying to connect to me using the same port number that i use, which is weird because i use an oddball number that was assigned by air.  thing is it's always from china and i could see if maybe a coincidence that someone could be using the same port as me if it only happened once, but i've seen it happen quite a few times and it's always from china.  

i guess my question is, is it someone trying to hack me or something? i figure that would probably be next to impossible being i'm already using vpn and firewall and what not. but if you were using your actual ip adress and they knew which port you had open is that something they could use to get in to your system?  really i know it's probably no big deal, just bugs me when i see it. 

2) i also see people sometimes that will be using both ipv4 and ipv6 address and showing up as two peers i guess to speed up their downloads, but to me that's cheating so i'll usually just ban one of the addresses and they can get one connection like everyone else.  my upload slots are limited so like i said seems like they're cheating.  kind of wonder how they get that to work, but really i'm fine with waiting 30 min or whatever it takes to get my free product without being a pushy a-hole.  reminds me of people that go through the 10 item express lane at the grocery store with 25 items. 

[Tech Jedi Alex 1543]

19 hours ago, d3adf1sh said:

but sometimes i'll notice after it's been up for a while i'll see a peer trying to connect to me using the same port number that i use, which is weird because i use an oddball number that was assigned by air.  thing is it's always from china and i could see if maybe a coincidence that someone could be using the same port as me if it only happened once, but i've seen it happen quite a few times and it's always from china.  

I remember you were based in China. Could it be your own ISP IP address there?
 

19 hours ago, d3adf1sh said:

i also see people sometimes that will be using both ipv4 and ipv6 address and showing up as two peers i guess to speed up their downloads, but to me that's cheating so i'll usually just ban one of the addresses and they can get one connection like everyone else. 

Nah, that's not how it works. If you're subscribed to your ISP's gigabit line for instance, you don't get one IPv4 gigabit line and one IPv6 gigabit line which then add up to be two gigabits – the same gigabit line is just reachable by two different address schemes, v6 preferred, but the quicker gets the traffic. No need to ban anything there.
At least for that reason – at the end of the day I think it's still taking two upload slots. Wondering how you know it's the same peer, though.

[d3adf1sh 1]

16 hours ago, Tech Jedi Alex said:

I remember you were based in China. Could it be your own ISP IP address there?
 
Nah, that's not how it works. If you're subscribed to your ISP's gigabit line for instance, you don't get one IPv4 gigabit line and one IPv6 gigabit line which then add up to be two gigabits – the same gigabit line is just reachable by two different address schemes, v6 preferred, but the quicker gets the traffic. No need to ban anything there.
At least for that reason – at the end of the day I think it's still taking two upload slots. Wondering how you know it's the same peer, though.

they have the same port and their completion rate ticks up at the exact same rate.  i use qbittorent so it shows you that stuff in the peers tab.  

and no i don't live in china   thankfully.

[Stalinium 58]

On 5/7/2026 at 12:31 AM, d3adf1sh said:

i'll see a peer trying to connect to me using the same port number that i use, which is weird because i use an oddball number that was assigned by air.

just make sure it's not your own exit IP (whether real IP or VPN exit IP) 🤣
 

On 5/7/2026 at 12:31 AM, d3adf1sh said:

thing is it's always from china and i could see if maybe a coincidence

there have been sightings of oddball servers that would mirror the exact traffic back to you. purpose: unknown. this would look really like your counterpart with the same port tried to connect to you.
Try to write down IPs to see if a pattern emerges. Is it a small range of addresses (first half of IPv6, entire address for IPv4 accounting) or a broad range? Do they belong to the same ISP or hosting?
 

On 5/7/2026 at 12:31 AM, d3adf1sh said:

2) i also see people sometimes that will be using both ipv4 and ipv6 address and showing up as two peers i guess to speed up their downloads, but to me that's cheating so i'll usually just ban one of the addresses and they can get one connection like everyone else.  my upload slots are limited so like i said seems like they're cheating.  kind of wonder how they get that to work, but really i'm fine with waiting 30 min or whatever it takes to get my free product without being a pushy a-hole.  reminds me of people that go through the 10 item express lane at the grocery store with 25 items. 

relax, stop over reacting, stop micromanaging and get used to it, because that's how the internet is supposed to work on a technical level

1. IPv4 and IPv6 are separate and independent networks. Your client is correct to treat them as if one doesn't know about the other
2. IPv6 hosts (peers) will often have at least two addresses assigned through no fault of their own. Your client is correct again to treat them separately as if they were independent but equal.
The above is correct on a technical level. The world won't get better if you start handing out manual bans to more fairly redistribute the upload bandwidth. The world will get better if more people contribute to uploading with more bandwidth.

You wanted an answer, right? The answer is: the bittorrent client could try to deduplicate peers across different logical networks only for the limited upload speed to be more fairly distributed across currently connected peers. Why isn't it being done? It's impossible and/or very hard and/or unnecessary. How many CPU cycles does a program need to dedicate to scanning all details between all peers for deduplication to avoid the bandwidth advantage of (Number IP addresses * 1/number total peer connections)? The difference is 1/n in most cases.

While it's apparent to you that a peer is the same over multiple addresses, to a program it is not. How do you avoid banning all of a real peer's addresses, when the remaining one drops completely for example? Like IPv4+IPv6 were working and connected, IPv4 was banned by you. But then the peer drops out, because IPv6 stopped working on their end. Do you lift the ban by retrying (wasting packets, CPU cycles and energy?). The solution asks for heuristics and for a computer and programmer it's muddy waters. Why spend time  and effort to begin with?

I have spent more effort than necessary by explaining this, but I wouldn't convince you otherwise, because you act on emotion of righteousness... understandable. unless you understand how futile your manual effort is. I don't mean to sound condescending, but the protocol works the way it does. It is what it is. And the person on the other end is not evil or responsible for how it works. At the planetary scale the solution is more seeding. Just keep seeding when you can. That's all, folks!